1. Technical Field
Various embodiments of the inventive concept relate to a method of fabricating a semiconductor integrated circuit, and more particularly, to a method of fabricating a phase-change random access memory (PCRAM) device including a phase-change layer.
2. Related Art
With the rapid development of mobile and digital information communication and the consumer-electronics industry, studies on existing charge-controlled devices have encountered limitations. Thus, new functional memory devices with novel concepts other than existing charge-controlled memory devices need to be developed. In particular, next-generation memory devices with large capacities, ultra-high speed, and ultra-low power need to be developed to satisfy the demand for large capacity memories.
Variable resistive memory devices using a resistance material as a memory medium have been suggested as the next-generation memory devices, and typical examples of variable resistive memory devices are PCRAMs, resistive RAMs (ReRAMs), or magnetoresistive RAMs (MRAMs).
A variable resistive memory device may be typically formed of a switching device and a resistance device, and may store data “0” or “1” depending on the state of the resistance device.
The goal of variable resistive memory devices is to improve integration density and to integrate as many memory cells as possible in a limited area.
Variable resistive layers in resistance devices, phase-change layers for example, are formed in various structures. Defining a phase-change region in an interlayer insulating layer and burying the phase-change material layer in the phase-change region has been the main method used.
With increasing integration density in variable resistive memory devices, the diameter (or a line width) of the phase-change region is constantly being reduced. Thus, there is a need for a method of burying a phase-change material in a narrow phase-change region without a void.